Device for indicating loss of tire air pressure



y mounted on the wheel of the vehicle for DEVICE FUR INDICATING LGSS OF TIRE AIR PRESSURE Andrew C. Wooden, Box 237, Little Falls, lVlinn. 56345 Filed Oct. 2, 1964, Ser. No. 40.115 4 Claims. (CL 340-58) The present invention relates to an improvement in a tire.

When a pneumatic tireis run withl the air pressure below normal, excessive wear isv caused and if tire pressure falls to nothing, further running completely destroys the tire. As thesize of vehicles for overland transportation, such as busses aud trucks increased, the size and quality of the pneumatic tires increased andthe cost of the same increased considerably. The maintenance of proper tire air pressure materially reduces tire cost.

It is an object of the invention to provide :t device indi-:ating a fall off in pressure in a tire` the loss in pressure actuating a transmitter which transmits a radio signal. This signal is picked up by a rt'teriliansmitter 1eyed to the same and located in close proximity to the wheels of the vehicle, the receiver-transmitter transmitting amsyignal to a receiver located in the cab of themiihidlfm'lilie rye''iver of the receiver-transmitter is of low device for indicating aloss of air pressure in' a pneumatic unit are not picked up and a. low sensitivity receiver can -be used because it is mounted on the vehicle with a minican occur. Y l

It will not be here attempted to setfforth and indicate all of the'various objects and advantages'incident to the invention, ferred to in or else will become apparent from ythat which follows. f f

The invention will appear more clearly from the fol lowing detailed description when taken in connection with the accompanying drawings, showing by way of example a preferred en lbodiment of the inventive idea wherein klike numerals refer to like parts throughout.

` ln the drawings forming part of this application:

FIGURE 1 is side elevation of a truck'lractor and semi-trailer illustrating the device thereon.

FIGURE 2 is a perspectlveview of that portion of the unit mounted on the wheel of the vehicle.

FIGURE 3 is a rear end view of the wheel unit.

FIGURE 4 is a plan view of the wheel unit, portions .f

thereof being broken away, other portions being in'scction. FIGURE 5 is a section on the line 5 5 of FIGURE 4.

sensitivity ,so that signalsv other than those from the transmitter of the wheel` tire vwith the loss in pressure canbe repaired before extensive damage man sfaese- Parano .axallyfrom the piston is the extension or rod 30. The i end of the rod which includes the bur 46 cut other objects ond. advantages will be re- FIGURE 6 is a section 'on the line 6-6 of FIGURE 4.

v FIGURE 7 is a section on the line 7-7 of FIGURE 2.

FIGURE Sis a view on the line 8-8 of FIGURE l showing the installation of the unit on the wheel of the vehicle.

Referring to the drawings in detail, the wheel unit A as part of the device for indicating a loss of tire pressure includes the body member of high impact plasttc. The body member 10 has formed therein the air inlet orifice 12 to which isrconnected-tbe short air line 14 which 1n turn is connected to the conventional valve stem 16 of the tire B of the outboard-wheel rim 13- which is connected to the inhoard wheel rim 20 mounting the tire C. Mounted in the body 10 is the inlating stem 22 which carnes a conventional valve core and which communicates with the inlet orifice 12. The valve core is removed from stem 16 and operates in stem 22. Leading from and mtxally disposedto the inlet orice 12 is the enlarged cylinder portion 24 of the block 10 in which is `positioned the .metal cylinder sleeve 26 and` which forms a cylinder.

- engaged inthe outer end of the rod 30 slidably extends through the axial hole 32 of the bushing 34 which is threadedly end of the slccve26. The hole 32 of the minates in an enlarged socket portion 36v the insulator 38 mounted on the` outer 30the movement of which will be herebushing 34 ter which receives inafter describe end of the rod 30 is the contact 40 spaced from the` insulator 38.

Further provided is the coil tension positioned on the'rod 30 and held captive between the piston '28 and the bushing 34 thereby urging the piston toward the air inlet hole l2. Sealing engagement of the piston 28 with the cylinder sleeve 26 is made by means'of the Ofrings 42 and 44 mounted in annular recesses formed in the piston 28. The bushing 34 is formed with holes for n Spanner wrench and as the bushing is screwed inwardly the tension on the spring 42 is increased and viceversa. Greater tension on the spring would require less fall oft in pressure to cause the piston and rod 30 to move to create asignal in the conventional transmitter T.

The transmitter T is battery battery B' and `housed within spring 42 whichlis operated by means of the the recess of body 10 on which is mounted the pair of contactors All and 50. Contact of contactor'48 is made between either insulator 38 or Contact 4t). The contactors 48 and 50 are connected to a conventional flange portions 62, 64 and 66, respectively, which engage in the grooves 68, `itl and 72, respectively` formed in the body 10. The cover 52 is thus slidablyfpositioned upon the body 10 with the flanges 62, 64 and 65 within the grooves 68, and 72, respectively. The cover 52 is secured in position by means of the screw 'I4 threadedly f engaged in the body 10 through a portion of the cap overlying the body. and tlze body 10 is accomplished by the elongated compressible gasket member 76 positioned in the recess 78 formed in the body 10 spaced from but adjacent the top edge of the recess 45.

The operation of the device is as follows: The tire B` is inflated through the inating stem 22 to pressure say of 110 lbs. This pressure is exerted against the piston 28 thereby K wardly against the tension or' the spring whereby thein-V stilator 38 is placed in contact with contact 48 thereby grounding out the transmitter. The tension of the spring 42 is such that it talles. for example, 110 lbs. of air pressure to maintain the piston 28 in the position with the insulator 38 in contact with the contactor 48 therebyv making the transmitter T inoperative as illustrated by the contact 38a, hereinafter described, in contact with com tact 56. The spring 42 is constructed so that when the air T T pressure ir. the tire B falls oli say to lbs., the *pistonv 12 to a position where contnctt'tt) V moves toward orifice y of rod 30 contacts contacter 48 of the har 46 of the, transmitter and energizes the transmitter T which transmits a signal to the conventional receiver-transmitter Dil-v D transmits the signal to the conventional receiver 'F y 3,329,934 Patented July 4,y 1967","

. Also positioned on the extreme outer Sealing engagement between the cap 52 forcing the same and the rod 3H reurcircuit not shown and by means of whichthe transmitter I i the proper i air pressure. When the tire is repaired or replaced, the

same is inated, and the piston 28 returned to the position shown for piston 28a hereinafter described with the insulator 38vin contact with contactor 48 of the transmitter T. s

The signal given off bythe transmitter T is one of low output and asa result the pickup of thefsame is by the receiver-transmitter D located as close `as possible and as A fall oil in air pressure in tire C on dual rim 20 isin` dicated by means of identical construction in the 'same body t0, the body l0 being mounted on the outboard wheel rim 18. The identical parts are given identical numbers accompanied in each instance bythe letter a. Short air line 14a is connected to the valve stem 80 of the tire C. Thus. the unit A serves both tires B and C. A unit A is used for each set of dual wheels. A signal transmitted by the transmitter of any of the units A of FIGURE l, for example, is picked up and transmitted by receivertransmitter D and transmitted to receiver F in the cab of tractor G. The driver ascertains by a simple visual or tapping check which tire has had a fall off in pressure.

The invention is not to be understood as restricted to the details set forth since these maybe modified within the scope of the appended claims without departing from the spirit and scope of the invention.

Having thus described the invention what is claimed as new and desired to be secured by Letters Patent is:

1. ln a device for indicating a loss in tire air pressure on a vehiclekcomprising:

(a) a body member having (b) :an air inlet orice leading to (c) a cylinder formed therein, v s

(d) means for connecting said air inlet orifice to the valve stem of a tire,

(e) a piston mounted in said cylinder and having t (i) a rod extending axially therefrom,

(g) means for introducing air into said air inlet orifice to actuate said piston and inate a tire through said connecting means,

(h) a bushing adjustably mounted in said cylinder and through which said rod freely extends, Y

y (i) an insulator member located on said rod,

(i) a contact member located on said rod,

(k) a signal transmitter mounted in said body member having a contactor member thereon,

(l) a coil spring mounted on said rod between said piston and said bushing urging said piston and rod thereon toward said air inlet orifice to bring said contact in contact with said contactor to thereby energize said transmitter upon a decrease in pressure on said piston, said transmitter being deenergized as a result of said insulator on said rod contacting said contactor due to an increase in air pressure upon said piston, and

ttoV

(m) means for mounting said body member on the wheel of a vehicle.

2. In a device for indicating a loss in tire pressure ona vehicle comprising:

(a) a body member having l fb) an air inlet oriliee leading to tc) a cylinder formed therein,

(d) means for connecting said air inlet orifice to the `valve stem'of atire,

(e) a piston mounted in said cylinder, v

(f) means for introducing air into'said air` inlet orifice to actuate said piston and inflate a tire through said connecting means,

(g) a signal transmitter mounted in said body member, l- (h) spring means urging said piston in one direction in y f said cylinder,

.I (i) said piston having an extension portion extendingY axially of the piston within said body member,

(j)V means carried by said extension portion for energizing said mnsmitter when said piston is moved in one direction by said spring means and a lowering of Apressure on said piston,

(k) means carried by said extension portion for dcenergizing said transmitter when said piston is moved in the opposite direction by an increase in pressure y and against the action ofv said spring means, and (l) means for mounting said body member on the wheel of a vehicle. 3. In a device for indicating aloss in tire air `pressure comprising in combination:

(a) a body member having (b) an air inlet leading to (c) a chamber formed therein,

(d) means for connecting said air inlet to the valvev one end thereof for deenergizing said signal trans-' miner upon increase in pressure in said chambery {i} a receiver f'nal transmitter for location on a vehicle on 'eine said signal transmitter is mounted in close proximity t: said body member for receiving a signal from said signal transmitter and transmitting said signaLand (j) a receiver for location in the cab of the vehicle for receiving signal transmitted from said receiver-transmirter.

4. In a device for indicating a loss in tire air pressure n on a vehicle comprising:

(g) means for introducing air into said air inlet orifice to actuate said piston and inate a tire through said connecting means, Y l (h) an insulator member located on said rod, (i) a contact member located on said rod,

(j) a signal transmitter mounted in said body member having a contactor'member thereon, l (k) means mounted on said rod urging said piston and rod thereon toward said inlet orificeto bring saidV contact in contact with said contacter to thereby energize said transmitter upon a decrease in pressure on said piston, said transmitter being deenergized as a result of said insulator on said rod contacting said` v contacter due to an increase in air pressure kupon said piston, and

(l) means for mounting said Vbody member on the wheel i ofa vehicle'. I y 4 i References Cited .mman srAres PAU-:Nrs

:2,966,658 tz/tsso oNein 34e-5s 3,215,978 11/1955 Brown et al. 340-58 i NEIL C. READ, Primary Examiner. i. t

rs A. H. WARING, ssamm Examiner., 

1. IN A DEVICE FOR INDICATING A LOSS IN TIRE AIR PRESSURE ON A VEHICLE COMPRISING: (A) A BODY MEMBER HAVING (B) AN AIR INLET ORIFICE LEADING TO (C) A CYLINDER FORMED THEREIN; (D) MEANS FOR CONNECTING SAID AIR INLET ORIFICE TO THE VALVE STEM OF A TIRE, (E) A PISTON MOUNTED IN SAID CYLINDER AND HAVING (F) A ROD EXTENDING AXIALLY THEREFROM, (G) MEANS FOR INTRODUCING AIR INTO SAID AIR INLET ORIFICE TO ACTUATE SAID PISTON AND INFLATE A TIRE THROUGH SAID CONNECTING MEANS, (H) A BUSHING ADJUSTABLY MOUNTED IN SAID CYLINDER AND THROUGH WHICH SAID ROD FREELY EXTENDS, (I) AND INSULATOR MEMBER LOCATED ON SAID ROD, (J) A CONTACT MEMBER LOCATED ON SAID ROD, (K) A SIGNAL TRANSMITTER MOUNTED IN SAID BODY MEMBER HAVING A CONTACTOR MEMBER THEREON, (1) A COIL SPRING MOUNTED ON SAID ROD BETWEEN SAID PISTON AND SAID BUSHING URGING SAID PISTON AND ROD THEREON TOWARD SAID AIR INLET ORIFICE TO BRING SAID CONTACT IN CONTACT WITH SAID CONTACTOR TO THEREBY ENERGIZE SAID TRANSMITTER UPON A DECREASE IN PRESSURE ON SAID PISTON, SAID TRANSMITTER BEING DEENERGIZED AS A RESULT OF SAID INSULATOR ON SAID ROD CONTACTING SAID CONTACTOR DUE TO AN INCREASE IN AIR PRESSURE UPON SAID PISTON, AND (M) MEANS FOR MOUNTING SAID BODY MEMBER ON THE WHEEL OF A VEHICLE. 